Amarantha - I think this would work great, unless the two 'A' names is an issue for you. It has the same kind of cadence as Aph, but is a very different name. It also has a kind of underlying strength to it, the same way Aph does.

Ceridwen- This would be a gorgeous choice with Aph, but it is another mythology one. But it's not Greek, so it feels less 'themey' than if you went in the Greek myth direction.

Circe- I know how much you love this name. And though I wouldn't personally suggest going in the direction of Greek mythological names so soon after Aph, if you really wanted a Greek myth name, this would be the one to go with I think.

Eulalia- This has a very different feel than Aph. It sounds a lot more princessy and flowery. Less strength than Aph. But it is a very distinct name in itself, and could work quite well. I'm actually a little surprised you like it so much, doesn't quite seem your style to me (and it doesn't quite seem to fit my style either, yet I also really like it).

Melusine- There's something about this name that just sounds like the right name to choose. I don't know why. I don't know anything about this name. But, to me, it just feels like it should be the name you choose.

Morgana- I like this name, and think it has some qualities that match up quite well with Aph. It's a very magical name.

Oriana- This is one of my favorite names. I think it'd be a great choice. It's got a quiet strength to it that allows it to stand up next to Aph well.

Xenia- It would be a bit Greek themey, but I just think this name is fantastic. I had a friend in college with this name, and always thought it was stellar.

On the fence about:Amoret- It's nice, but not great with Aph. Also a bit too 'word' sounding to me (amor).
BellicentFiammetta- This one is new to me, and I think it could really grow on me. If I let it sit a bit, it might move up to the above category.Genoveva- I think I prefer the sound of Genevive (sp?), but this is nice too.
Gwenllian
Lyonesse- Has an inner-strength which I really appreciate. Tanaquil- I really want to live this name more, but I can only like it a moderate amount.

Don't like so much (Many of these I might have different opinions on if I knew more about them, but my first impression is not wonderful):Atalanta- Sounds like a strange version of Atlanta.
BelphoebeBoudicca- sounds too much like bodacious
Euphrosyne
FlorimellGodiva- Feels weird next to Aphrodite to me.
HesperaHypatia
Liriope
Melpomene
Messalina- Sounds/looks like Alina's mess.
Niniane- Maybe I'm pronouncing it wrong, but it almost sounds like it should be a dirty word.Olympia- I like it, but not with Aphrodite. Way too Greek themey.Pandora- Not with Aphrodite.
Polyhymnia- Weird. Roxana- Doesn't feel significant enough to stand next to Aph.Selene- Same as above.Titania- Wouldn't wanna start a name with 'tit'Zenobia- Sounds like some sort of phobia.

Congratulations on number 2... We had hoped to have 2 very close together but our little Bug is 9mnths and still no magic... Yet...
It will be a busy few years for you but I think two babies close together has more pros than cons. Roo will not be old enough to get jealous or possessive of a newbee, and together they will have a life time of fond memories. Anyways back to the business at hand. Names! Aphrodite and: